This invention relates to the fundamental principles of combining different types of energy and systems for converting energy into power, and more particularly for converting heat energy into electric power energy, mostly with gravitational acceleration, according to improvements of the methods and systems disclosed in South African patent number 97/1984 and patent application 98/8561 which has not been published.
Denotation: Represent depth below surface by z, measured positive downwards; g to denote gravitational acceleration and m to be mass. For purposes of this application the term:
xe2x80x9cNxe2x80x9d is the ratio of two energy values like two latent heat values;
xe2x80x9cT-s diagramxe2x80x9d means the presentation on a graph with scales of temperature and entropy, of the state of condition of a fluid subject to variable temperature and energy levels;
xe2x80x9cWorkxe2x80x9d is one of the forms of energy;
xe2x80x9cCyclexe2x80x9d means a thermodynamic T-s cycle as presented in a T-s diagram and/or a mass circulation system operating in a closed loop;
xe2x80x9cPreheatingxe2x80x9d means to increase the energy and/or entropy of a fluid;
xe2x80x9cDrenchingxe2x80x9d means the addition of low entropy fluid(s) to a high entropy fluid(s) to reduce the high entropy of the formed fluid. The lower level of the high entropy limit of the entropy state of condition can also be reached by heat extraction and/or incomplete heat supply to fluid,
xe2x80x9cPower Cyclexe2x80x9d includes thermodynamic cycle(s) employed to produce more output power than power consumed to complete the cycle. In the xe2x80x9cconventionalxe2x80x9d power cycle fluid is pressurised, vaporised or gassified by the addition of heat, depressurised to do work, liquefied by the removal of heat in a continual process to form a cycle. In this document the power cycle includes a cycle in which low entropy fluid, preheated and drenched to any convenient level, is pressurised mostly by gravity, the pressurised fluid is partly depressurised to produce power, heated to higher entropy level by addition of heat, depressurised further by elevation against gravity, fluidised or liquified by the removal of heat in a continual process to form a cycle. The entropy extent of the power cycle is conveniently reduced to a more profitable value by preheating and/or drenching to produce less netto work per cycle and to produce globally more work per co-operating countercycle of a refrigeration fluid.
xe2x80x9cRefrigeration Cyclexe2x80x9d means a xe2x80x9cconventionalxe2x80x9d cycle that discards heat at high, or high and intermediate temperature(s), consumes heat at low, or low and intermediate temperature(s) and consumes and produces heat and work in circulation. fluid(s),mostly gas or vapour at high entropy level is pressurised to a significant extent by gravity in being lowered in a column, is vaporised or liquefied to be a low entropy fluid by the release or rejection of heat, to become a liquid and/or vapour or pre-heated vapour, in order to be of decreased entropy, the low entropy fluid becomes pressurised mechanically and depressurised to a significant extent by gravity, in moving up a column, the depressurised fluid heated by receiving heat to become a gas or vapour or drenched to be a high entropy fluid, recirculated to become a continual cycle.
xe2x80x9cCountercyclexe2x80x9d mens a cycle running in the opposite sense compared to another cycle. In this document a countercycle includes two thermodynamic cycles operating as a combination as a power cycle and a refrigeration cycle, mostly in the sense that the refrigeration cycle prescribes the operation of the power cycle and the combined countercycle consumes heat and produces power. Commonly the temperature range of the refrigeration cycle must be cooler at the cold end and hotter at the hot end of the two thermodynamic cycles. In this document the dominance of the refrigeration cycle over the power cycle is maintained in the sense that power input to the refrigeration cycle maintains the running of countercycles, even if the two or more cycle fluids are mixed to operate at the same temperatures.
For purposes of this application Countercycle Power Production is obtained by running a power T-s cycle inside or up to the boundary of a refrigeration T-s cycle.
Heat engines and refrigeration systems are well known in the art and have been subjected to extensive theoretical analysis. Typically the systems operate on closed circuits of fluid.
With heat engines the fluid is pressurised and then heated, to cause an increase in temperature and pressure. The pressurised fluid is then made to do work, usually by driving a turbine whereafter heat and energy is removed from the system to be pressurised again. Generally, the fluid will be in a liquid state before heating and in a gaseous or superheated gas state after heating.
With refrigeration systems a fluid in gas and/or fluid state is compressed mechanically and/or mostly by gravity, which heats the fluid. Heat is removed in a heat exchanger and/or fluid mixer and discarded from the refrigeration fluid. Thereafter the compressed fluid is depressurised mostly against gravity and/or to do work and cool by evaporation. At the lower pressure the fluid is allowed to vaporise partially or in whole to consume heat at low temperature. The low pressure vapour and/or liquid is then pressurised mechanically and/or by gravity to repeat the cycle.
Typical examples of the use of heat engines are power stations, and of refrigeration systems are household refrigerators. Some mine cooling systems performs work to reduce the internal, potential, velocity and/or gravitational energy.
Although the power and refrigeration systems tend to function well, they also tend to be inefficient due to a number of factors, such as mechanical and thermodynamic inefficiencies inherent in equipment used to do work, and the need to reject heat and/or energy.
South African patent number 97/1984 discloses a method of performing work in a cyclic manner. The method being characterised in that the gas and liquid are pressurised to a significant extent by the action of gravity in columns.
State of the art features applied are hysteresis loops, velocity energy, and common T-s diagram applications.
A yet further feature of the above patent provides for heat flow into the cycle(s) to be used in energy conversion, applying countercycles of fluid at different temperature values, consuming low grade heat and even in freezing water in the process of producing electric power.
The above patent further provides for a system for performing work substantially as described above comprising a closed circuit defining a flow path, the circuit being oriented to have an upper and a lower end and such that the action of gravity will cause a predetermined pressure difference in a fluid contained therein between the ends of the flow path.
The patent therefore includes gravitational refrigeration of water and power generation in countercycles by applying fluids having dissimilar latent heat exposures. The new application claims new versions of the above which change the application of the academic principles to become practical production units as described in the examples, and displayed in the figures.
The applicant""s co-pending South African complete patent application number 98/8561 has not been accepted and has not been published. It describes methods for performing work by the countercycle method including drenching of the power cycle up to 50%. The present application describes variable drenching and/or preheating up to or more than 50%, the gas and liquid being pressurised and depressurised to a significant extent by the action of gravity, the method being characterised in that the density of the fluid in the column is increased by drenching the vapour with a liquid component of the fluid or drenching it by a catalyst fluid or drenching it by any fluid. The new application includes drenching by internal countercycles of similar fluid(s) or mixtures of fluids exceeding 50% drenching.
The unpublished patent application 98/8561 further discloses a method for performing work in thermodynamic countercycle in which temperature differences for heat transfer are obtained by applying two fluids with different rates of heat increase for shaft depth increase, applied in a manner which causes heat flow at shallow depth from one fluid to the other and at greater depth to cause reverse heat flow between the fluids. This has now been extended to fluids of similar rates of heat increase and for a continuous variation in fluid mix entropies.
The proceeding definitions of terms and figures are applied onwards without limiting the invention by the abbreviated descriptions. The description of the examples and figures are local descriptions only. The basic theories will apply universally and beyond the examples.
The state of art including patent ZA971984 is illustrated in FIG. 1 and in the following example which is theoretically correct but unpractical.
State of the art example: From patent ZA971984, example 2 it is calculated that power can be produced as shown diagrammatically in FIG. 1 of this document. Columns or shafts of 3574 meters length numbered 2, 3, 4 and 5 are filled with C318 gas and/or vapour, C318 liquid, HFC134a liquid and HFC134 vapour and/or gas. Input heat exchanger 8 balances the power energy withdrawn at 9. Heat transfer occurs in heat exchangers 6 and 7. The power yield is 14.8 kJ/kg. The unappropriated shaft lengths and heat exchangers 6 and .7 are addressed in this text and in FIGS. 14 and 17 of this application.
In thermodynamics most operations involving heat may be typified in the classic T-s diagram shown in FIG. 3 by state At condition points 20, 21, 22, 23, 24, 25 and 20.
The teams of xe2x80x9cpreheatxe2x80x9d and xe2x80x9cdrenchxe2x80x9d are shown in FIG. 3. If heat is applied at 20 the fluid becomes preheated to (say) state of condition 26. If power (pressure i.e. work) is applied at 26 the state of condition chance to 27 which is also a state of condition of preheat. The entropy of 20 and 21 is increased at 26 and 27. Similarly the state of condition xe2x80x9cgasxe2x80x9d at 24 and 25 is changed to xe2x80x9cvapourxe2x80x9d by withdrawing heat, to state of conditions 23, 28 and 29. The new term xe2x80x9cdrenchingxe2x80x9d implies that the high entropy of superheated gas or gas at state of conditions 24, 25 and 23 is decreased. The application of preheating and drenching eventually change the shape of the convention T-s diagram to a rectangular or square shape like 26, 27, 28, 29, 26. This T-s shape modification eliminates superheating and it is hereafter commonly applied. Patent 97/1984 states that a refrigeration cycle encircles a power cycle(s) as shown in T-s diagrams in FIGS. 4 and 5.
A significant point of the state of art is illustrated in FIGS. 6, 7 and 8. The conventional condition of state T-s diagram 47 and the conventional shaft length 48 are in conflict as shown by the dotted liens between 47 and 48. The display change of 47 to 49 by rotation or inversion as defined in patent ZA971984 brings dimensions in correspondence.
The T-X hysteresis loop in FIG. 18 is common but its application in FIG. 20 is new. Components of energy are well known. Reference to potential energy in the form of gravitational acceleration and of velocity energy created in jetting, are applied in the inventions.
It is an object of the present invention to provide methods and systems for converting heat into electric power, by extending the state of the art with improvements to and additions to the methods and systems disclosed in previous patents. It exceeds on previous patents in proposing workable power generation layouts and refrigeration layouts which invite stray heat to be converted to power in 4, 3 or 2 operating shaft layouts. This utilises detailed information of the behaviour of practical thermodynamic fluids, and applies changes in material behaviour associated with induced changes in property and entropy levels of fluids and catalysts.
The invention is expanding the state of the art information and new methods. The invention includes principles of invented theory, heat balance induction, practical designs, internal countercycles, new techniques to multiply output with the application of preheated and drenched countercycles, etc. The cycles are driven by internal heating on applying gravitational compression on reshaped and equal temperature T-s diagrams. This magnifies output as shown in FIG. 9. The two column countercycles are based on new interpretations of hysteresis loops subject to gravitational acceleration applying N times countercycles and controlled by regulated temperatures at the top and bottom of shafts as shown in FIGS. 19 and 20. The preferred three column layout is utterly manageable by controlling only the pumping rate. It applies the new internal countercycle T-s diagram principle shown in FIG. 13. The new fluids composition in the three column layout, may consist of any single or multi-mixed substance qualifying only to safety, inflammability, specified viscosity, density etc. The latter xe2x80x9cdensityxe2x80x9d becomes a design feature in so far as, increased pressure limits the physical layout size and improves performance. Ammonia, for example can be pressurised to decrease the vapour volume from 323 liter/kg at 0.382 Mega pascal to 25 liter/kg at 4.8 Mega pascals. Carbon dioxide as a monofluid in countercycle operates at temperatures below the temperature of the surround and this invites the entry of stray energy. The design pressurising fits the state of the art knowledge on pressure underground in mines and applied in rock engineering as well as with new invented feature to supply power xe2x80x9con the jobxe2x80x9d without contaminating the environment. The substances ammonia and carbon dioxide lend themselves to catalyst action by water. The invention extends to all fluids.